Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) were conducted on two common types of rye straws (Danko and Kustro) at a heating rate of 20 degrees C/min in an oxidizing atmosphere (15% oxygen and 85% nitrogen, by volume) between ambient temperature and 700 degrees C. The two step nature of the TGA curves and the dual peak characteristics of the DTA curves showed that rye straw had two distinct reaction zones. The initial degradation temperatures, the residual mass at 700 degrees C, the thermal degradation rates in the first and second reaction zones and the kinetic parameters of each reaction zone (order of reaction, activation energy and pre-exponential factor) were determined. Higher thermal degradation rates were observed in the first reaction zone as compared to those in the second reaction zone.